With the development of the electronic technologies, portable consumer electronic devices are more popular and desired by people. A portable consumer electronic device, such as a wireless communication device, generally includes a vibration motor sued for generating tactile feedback.
Typically, flat linear vibration motors are commonly used. A flat linear vibration motor includes an elastic member, a vibration unit suspended by the elastic member, and a housing for accommodating the elastic member and the vibration unit therein. The elastic member is generally welded to the vibration unit. Such a vibration motor only has one resonant frequency, at which the vibration motor has maximum vibration amplitude. For some certain applications, the vibration motor needs two resonant frequencies for performing desired requirements. Such a typical vibration motor, as described in JP Publication No. 1993-85192, cannot satisfy the requirements.
For this reason, it is necessary to provide a novel vibration motor to overcome the shortcomings above.